Greg,
The reason it's so slow is because there is no command provided by Empeg that sends a list of all songs through the serial connection. The minute there is such a thing, I will implement it.
The way it works, now, the Palm app, starts at the beginning of the play list, pauses the song, then moves to the next one. This process is slow, plus, if the Palm app moves too fast through the list, it gets desynchronized with the RioCar unit. I had to put a reasonable timeout period of a second for that reason.
The HotSync conduit, however, is much more faster, because it simply reads from a file (c:\playlist.txt), and sends it directly to Palm. May be that's what you should use for now, since you have so many songs.
Let me know about any other issues you might have.